Fuel and other types of liquid storage tanks are typically tested for product depth by placement of a calibrated length dip stick into the tank through one of the access ports defined in a tank wall. The contacting of the tank bottom during this product depth measurement process initiates and accelerates corrosion activity in the bottom of the storage tanks, particularly when and where moisture accumulates through condensation and other moisture introduction processes.
Both industry standards and state regulatory agencies require placement of steel wear plates directly under each access port to prevent this corrosion accelerating process on the bottom of each tank. However, corrosion has also been found adjacent to or under these corrosion wear plates due to the development of corrosion inducing microbacteria and other galvanic corrosion inducing processes. Corrosion also occurs elsewhere in the tank such as adjacent seams or at other points therein.
It is not uncommon for water to accumulate at the bottom of an underground storage tank. Although the water depth is somewhat minimal, often less then one inch, it promotes corrosion in the tank wall.
There is a need to further protect against mechanical damage and corrosion to fuel or other types of liquid storage tanks at the location of wear plates and elsewhere throughout the tanks. There is also a need to improve the corrosion resistance of wear plates themselves.